import com.fasterxml.jackson.databind.ObjectMapper;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;

/**
 * Created with IntelliJ IDEA.
 * Description:
 * user:likai
 * Date:2023-01-02
 * Time:9:14
 */
@WebServlet("/userInfo")
public class UserInfoServlet extends HttpServlet {
    private ObjectMapper objectMapper=new ObjectMapper();
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //获取用户信息
        String blogId =req.getParameter("blogId");
        if(blogId== null){
            //列表页，获取当前登录用户信息
            // 直接从会话中获取
            getUserInfoFromSession(req,resp);
        }else{
            //详情页，获取文章信息
            //查询数据库
            getUserInfoFromDB(req,resp,Integer.parseInt(blogId));
        }
    }

    private void getUserInfoFromDB(HttpServletRequest req, HttpServletResponse resp, int blogId) throws IOException {
        //根据blogId查询blog对象，获取到userId
        BlogDao blogDao=new BlogDao();
        Blog blog= blogDao.selectOne(blogId);
        if(blog==null){
            resp.setStatus(404);
            resp.setContentType("text/html;charset=utf8");
            resp.getWriter().write("blog不存在");
        }

        //根据userId查询User对象
        UserDao userDao=new UserDao();
        User user=userDao.selectById(blog.getUserId());
        if(user==null){
            resp.setContentType("text/html;charset=utf8");
            resp.getWriter().write("blogId不存在");
            return;
        }
        //把user对象返回给浏览器
        user.setPassword("");
        resp.setContentType("application/json;charset=utf8");
        resp.getWriter().write(objectMapper.writeValueAsString(user));
    }

    private void getUserInfoFromSession(HttpServletRequest req, HttpServletResponse resp) throws IOException {
        HttpSession session=req.getSession(false);
        if(session==null){
            resp.setStatus(403);
            resp.setContentType("text/html;charset=utf8");
            resp.getWriter().write("当前未登录");
            return;
        }
        User user=(User)session.getAttribute("user");
        if(user==null){
            resp.setStatus(403);
            resp.setContentType("text/html;charset=utf8");
            resp.getWriter().write("当前未登录");
            return;
        }
        //获取到用户之后，可以删除密码
        user.setPassword("");
        resp.setContentType("application/json;charset=utf8");
        resp.getWriter().write(objectMapper.writeValueAsString(user));
    }
}
